I try to let him off as often as possible but I can only do it in quiet places because he wants to play with everyone he meets and puts muddy paws on them.

If you is the aggressive type, it's never a good decision to let them lead off in public places. There's a big risk it may bite someone and that's not a mess you should be getting into in the public. Kids being there is another thing to consider because some are afraid of dogs.

It depends on the place we are outdoor that's going to determine if I would let my dog off his leash. I wouldn't want to cause any scene in the public to avoid getting into any trouble. 

My dog is always very calm both in doors and outdoors. It makes it easier for me to even go without a leash on him when I'm out. He doesn't chase or bark unnecessarily unless it's important. 

I barely let my dogs out in public places. It's when I'm taking them for a walk that they get the chance to mingle in the public. Sometimes, I would let them go off on their own. They are well behaved. They don't go looking for trouble.